test alerts & confirms in poltergeist & capybara webkit

alerts_and_confirms.rb

module AlertConfirmer
  class << self
    def reject_confirm_from &block
      handle_js_modal 'confirm', false, &block
    end

    def accept_confirm_from &block
      handle_js_modal 'confirm', true, &block
    end

    def accept_alert_from &block
      handle_js_modal 'alert', true, &block
    end

    def get_alert_text_from &block
      handle_js_modal 'alert', true, true, &block
      get_modal_text 'alert'
    end

    def get_modal_text(name)
      page.evaluate_script "window.#{name}Msg;"
    end

    private

    def handle_js_modal name, return_val, wait_for_call = false, &block
      modal_called = "window.#{name}.called"
      page.execute_script "
      window.original_#{name}_function = window.#{name};
      window.#{name} = function(msg) { window.#{name}Msg = msg; window.#{name}.called = true; return #{!!return_val}; };
      #{modal_called} = false;
      window.#{name}Msg = null;"

      block.call

      if wait_for_call
        timed_out = false
        timeout_after = Time.now + Capybara.default_wait_time
        loop do
          if page.evaluate_script(modal_called).nil?
            raise 'appears that page has changed since this method has been called, please assert on page before calling this'
          end
          
          break if page.evaluate_script(modal_called) || 
            (timed_out = Time.now > timeout_after)

          sleep 0.001
        end
        raise "#{name} should have been called" if timed_out
      end
    ensure
      page.execute_script "window.#{name} = window.original_#{name}_function"
    end
  end
end

example_usage.rb

# this should catch the following alert
#
# <button onclick="alert('totally alerted')">make an alert happen!</button>
#

AlertConfirmer.get_alert_text_from do
  click_buttton 'make an alert happen!'
end.should == 'totally alerted'

Thanks @michaelglass for the awesome hack to work around Poltergeist's glaring deficiency here!

@tesserakt I deleted the class << self block and saved the file as spec/support/alert_confirmer.rb. Then I told RSpec to load it like so:

RSpec.configure do |config|
  config.include AlertConfirmer, type: :feature
end

and now I can use the helper methods directly in my feature specs (i.e. accept_confirm_from do ... end instead of AlertConfirmer.get_alert_text_from do ... end).

@abevoelker I used this moudle like you

 accept_confirm_from do
      click_buttton 'confirm'
    end

but when I run this test. there is a error:

 NoMethodError:
       undefined method `click_buttton' for #<RSpec::ExampleGroups::FindRoom:0x007fe7bb97e960>

@fgcui1204 I was getting the same error. I had to include the alerts_and_confirms.rb file in my support folder and remove the class << block. Then I could use accept_alert_from do...